1. Technical Field
The present invention relates to a wire structure. More particularly, the present invention relates to a wire structure and a design method thereof, wherein enhanced heat dissipation is achieved in the micron scale by an irregular shape design and by changing the surface area as appropriate.
2. Description of Related Art
The continuous improvement of technology has given rise to a plethora of electric appliances and electronic products. An electronic product typically requires a plurality of wires for transmitting signals and thereby achieving the intended hardware and software objectives.
Conventionally, a wire structure depends on an external heat exchange structure, such as a fan or fins, to dissipate heat, and the purpose of providing the additional heat exchange structure is to increase the efficiency of heat transfer.
However, when wire structures are downsized to the micron scale (about 0.010 to 0.999 mm), the issue of heat dissipation differs substantially from that of the traditional wires, which are in the millimeter scale (about 1 to 2 mm). This difference can be accounted for by the fact that heat transfer in different scales features different heat dissipation effects. Besides, the additional heat dissipation structures incur extra costs and occupy considerable space, which is highly undesirable.
U.S. Pat. No. 7,479,597 discloses a wire structure whose cross section is defined by a closed curve composed of three to eight convex portions and an equal number of concave portions. The radii of curvature of the convex portions and of the concave portions are less than one sixth of the overall radius of the closed curve. The radius of the cross section of the wire ranges from 2 mm to 10 mm. Moreover, the radii of curvature of the convex portions and of the concave portions can be less than 0.1 mm.
It is well known that the heat dissipation effect of a wire varies with the surface area of the wire structure. If the dimensions of the wire structure of the '597 patent are markedly reduced (e.g., to one tenth, one hundredth, or even one thousandth), the perimeter of the closed curve will become so small that an increase in the surface area of the wire structure is unattainable by the design of the convex portions and the concave portions, and poor heat dissipation follows. If, however, an additional heat exchanger is used for more efficient heat dissipation, the convenience of use of the electric appliance in which the wire structure, and hence the heat exchanger, are provided will be compromised. Therefore, it is a pressing issue to improve heat transfer of relatively small wire structures.